Airflow and noise controlling plenum diffuser assembly



United States Patent This invention relates to a novel airflow and noise controlling diituser assembly for plenum air conditioning sys terns, and the like.

The primary object of the invention is the provision of eflicient and practical assembly of the kind indicated, which is easily installed, and has damper means which is readily adjustable to determine the rate of flow out of a room or other building area.

Another object of the invention is the provision of an assembly of the character indicated above having a novel multiple baffle air diffuser which produces even spread or distribution of air into a room.

A further object of the invention is the provision of an assembly of the character indicated above which includes a non-breathing panel adapted to be installed in an opening in the wall of a plenum, the panel having an opening in which the diffuser housing is engaged, the diffuser housing being secured to and in direct communication with a fibrous material open-ended conduit, located within the plenum, the housing being supported by elongated strut means, secured to the housing behind the panel, which bears throughout the length thereof on the panel, with opposite ends of the panel resting upon supporting means, such as T-bars, whereby the weight of the assembly is widely distributed.

Other important objects and advantageous features of the invention will be apparent from the following description and the accompanying drawings, wherein, for purposes of illustration only, a specific form of the invention is set forth in detail.

In the drawings:

FIGURE 1 is a perspective view of an assembly of the present invention installed in a ceiling, the conduit being shown in longitudinal position in full lines and in trans verse position in phantom lines:

FIGURE 2 is an exploded perspectiveview of the assembly;

FIGURE 3 is a vertical section taken on the line 3-3 of FIGURE 1;

FIGURE 4 is a vertical section taken on the line 4-4 of FIGURE 3.

Referring in detail to the drawings, wherein like numerals designate like parts throughout the several views, the illustrated assembly, generally designated 10, is shown installed in a ceiling wall 12 of a plenum 13, having an opening 14, along opposite ends of which supported T- bars 16 extend, which have lateral flanges 18.

The assembly comprises a panel 20, of non-breathing construction, which fits the opening, 14, and rests, at its ends, upon the T-bar flanges 18. The panel 20 has a central rectangular opening 22 in which a hollow rectangular, open-ended housing 24 fits. The housing 24 has a surrounding lateral flange 26, around its outer end, which has a peripheral rib 28, on its inward side, which bears against the outer surface of the panel 20.

Channel struts 32, which are as long as the panel 20, are bolted, as indicated at 34, to opposed walls 36 of the housing 24, and bear against the upper or inner side of walls 36 of the housing are provided with vertical rows of bolt holes 38, for selectively receiving the bolts 34,

3,177,795 Patented Apr. 13, 1965 so asto accommodate the struts 32 to panels 20 of different thicknesses.

The inner end 40 lofthe housing 24 is engaged in a,

rectangular opening 42, provided in the lower part of a rectangular horizontal air conduit 44, the conduit 44 being adapted to be positioned crosswise of the housing 24, in either direction, as indicated in FIGURE 3. The air conduit 44 comprises an outer shell 46 of metal foil or other impermeable sheet material, to which is suitably secured a relatively thick liner 48 of fibrous sound-absorbing material. The conduit 44 rests upon the top of str-uts 32. As shown, the conduit 44 can be only slightly longer than the panel 28 or shorter than the panel20', or substantially longer than the panel 20, as indicated by the situation, and has open ends 50, which communicate with the plenum 13;

The housing 24 has a diffuser assembly'52 positioned within and extending outwardly or downwardly from the outer or lower end of the housing 24. The diffuser assembly 52 comprises a plurality of nested, concentric frusto-pyramidical baffles, such as the inner bafile 54 and the outer bafile 56, Witha flat rectangular center bafiie plate 58 centered across the outer end of the outer baffle 56. It will be understood that the present invention contemplates also a circular housing 24 and circular, frustoconical bafiles.

The bafiles 54 and 56 have concentrically spaced tubular necks 60, on their inner or upper ends, and have horizontal, parallel spaced peripheral flanges 62 around, their outer or lower ends. The baffles 54 and 56 are supported on arms 64 which extend inwardly from the opposed walls 36 of the housing 24, at slight downward or outward angles, relative to the horizontal, the upper or inner edges of the necks 60 being suitably fixed to the arms 64. The center baffle plate 58is smaller in area than the outer or lower end of thelower baffle 56, and is secured, as indicated at 66, to the outer baffle 56, at the outer or lower end thereof. It will be understood that the peripheral channel provided between the inner or upper baffle 54 and the housing flange 26, and the peripheral channels between the inner baflie 54, the outer baffle 56, and the center baffle plate 58, produces initially hollow and initially conical airstreams which spread out throughout a room, so that air discharged from: the housing 24 is more uniformly and evenly distributed throughout the room.

For controlling the amount and rate of flow of air into a room, through the housing 24, and the diffuser assembly 52, adjustable damper means is mounted Within the housing 24, inwardly or upwardly from the diffuser assembly 52. The damper means comprises a pair of similar elongated flat rectangular damper plates 68, which extend longthwise between the opposed walls and 72 of the housing 24, and are in side-by-side relationship. As shown in FIGURES 3 and 4, centered lateral cars 74 are fixed on the ends of the damper plates and extend downwardly or outwardly therefrom, and are pivoted to the housing walls 70 and 72, as indicated at 75 at points which are spaced at equal distances from the housing walls 36 and close to the upper or inner end 40 of the housing 24. At their ends adjacent to the housing wall 78, the damper plates 68 have off-center lateral cars 78, located at the inner or upper sides of the centered ears 74, and links are pivoted, as indicated at 82, at their upper or inner ends to the cars 78. The links 80 converge outwardly or downwardly and their overlapped lower or outer ends are traversed by a pivot pin 84, which extends through the free ends of an arm 86 of a bellcrank lever 88, which has another arm 90, which extends downwardly or outwardly, in the space between the necks 60 of the diffuser bafiles 54 and 56, so as to be reachable for rotating the bellcrank lever, in opposite directions, on the axis of a mounting pivot 92 which is fixed to and extends laterally inwardly from the housing wall. Rotating the bellcrank lever 88 clockwise, as seen in FIGURE 4, moves the damper plates 68 toward each other, and toward a horizontal plane, wherein the flow of air from the conduit 44 and through the housing 24 plates and between the damper plates and the housing Walls 36.

It will be understood from the foregoing that air back pressures and pulsations produced by the intervention of the dilfuser assembly 52 and the damper plates 68 in the air present in the conduit and in the housing 24, which would otherwise produce vibration of the walls of the conduit and the housing 24, and accompanying noise, are cancelled by the sound absorbing liner 43 of the conduit 44.

Although there has been shown and described a preferred form of the invention, it is to be understood that the invention is not necessarily confined thereto, and that any change or changes in the structure of and in the relative arrangements of components thereof are contemplated as being within the scope of the invention as defined by the claim appended hereto.

What is claimed is:

A noise and airflow controlling essembly comprising, in combination'with a false ceiling having a plurality of panels, one of said panels having an opening extending transversely therethrough, and spaced elongated panel support means for supporting said panels, said assembly including a tubular housing having a pair of opposed open upper and lower ends and pairs of opposed walls, saidrhousing having the said lower end thereof fitted within said opening with its upper end projecting above said one panel, arms projecting inwardly from a pair of said opposed walls and being fixedly secured to said walls, a plurality of vertically-spaced concentric frustopyramidal bafiles each having upwardly-extending con- Al centrically-spaced tubular necks, said necks being connected to saidarms to suspend said baffies below said lower end of said housing, a pair of elongated fiat damper plates extending lengthwise between another pair of said walls of said housing, said damper plates being posif tioned in side-by-side relationship, means pivotally connecting said damper plates to said other pair of opposed walls, a pair of elongated substantially rectangular links having one of their ends pivotally connected respectively, to one of said damper plates, means p'ivtolly connecting the other ends of said links, a bell-crank lever having one of its ends pivotally connected to saidlast-narned means, means pivotally connecting the central end of said bellcrank lever to one of said first pair of walls, and the other end of said bell-crank lever being manually-operable to effect the pivotal movement of said damper plates toward and away from one another, an elongated air-conducting conduit having an opening formed therein, a sound-ah sorbing liner disposed within said conduit and secured thereto, said upper end of said housing being fitted within said opening formed in said conduit, and elongated means disposed between said conduit and said one panel support ing said conduit in vertically-spaced relation relative to' said one panel, said means comprising an elongated member secured to the opposite pair of walls of said housing and extending above said panels between and to a pair of adjacent panel support means and being supported thereon.

References Cited by the Examiner UNITED STATES PATENTS 7 2,621,579 12/52 Person et al. 98-40 2,661,677 12/53 Lingelbach 98114 2,750,865 6/56 Tutt 18l50 X r 2,852,999 9/58 Lowensohn 9840 2,872,859 2/59 Kennedy. 2,920,357 1/60 Ericson. 2,928,331 3/60 Averill 98-40 ROBERT A. OLEARY, Primary Examiner.

CARL W. ROBINSON, Examiner. 

